Centos7下配置tgtd支持thin provision（scsi unmap）

野性酷女 2022-05-30 04:42 127阅读 0赞

# 操作环境 #

CentOS Linux release 7.4.1708 (Core)
    Linux centos7-nfstest 3.16.55 #1 SMP Sun Mar 4 23:15:32 EST 2018 x86_64 x86_64 x86_64 GNU/Linux

tgt

[root@centos7-nfstest ~]# tgtadm --version
    1.0.55

# 操作步骤 #

配置tgtd支持thin provision，tgtd后端必须使用文件系统类型，不能是硬盘。并且文件系统必须支持FALLOC\_FL\_PUNCH\_HOLE，下面是支持FALLOC\_FL\_PUNCH\_HOLE的文件系统

Not all filesystems support FALLOC_FL_PUNCH_HOLE; if a filesystem
           doesn't support the operation, an error is returned.  The operation
           is supported on at least the following filesystems:
    
           *  XFS (since Linux 2.6.38)
    
           *  ext4 (since Linux 3.0)
    
           *  Btrfs (since Linux 3.7)
    
           *  tmpfs(5) (since Linux 3.5)

本次实验采用的xfs文件系统。

1.安装tgtd

[root@centos7-nfstest ~]# yum -y install scsi-target-utils

2.创建backstore文件，该文件存储在支持xfs文件系统的设备上。

[root@centos7-nfstest ~]# tgtimg --op new --device-type disk --type disk --size 5120m --file /mnt/big_disc_file1.tgt

3.修改tgtd配置文件

[root@centos7-nfstest ~]# vi /etc/tgt/targets.conf 
    # This is a sample config file for tgt-admin.
    #
    # The "#" symbol disables the processing of a line.
    
    # Set the driver. If not specified, defaults to "iscsi".
    default-driver iscsi
    
    # Set iSNS parameters, if needed
    #iSNSServerIP 192.168.111.222
    #iSNSServerPort 3205
    #iSNSAccessControl On
    #iSNS On
    
    # Continue if tgtadm exits with non-zero code (equivalent of
    # --ignore-errors command line option)
    ignore-errors yes
    include /etc/tgt/conf.d/*.conf

4.在tgt的conf.d目录下，修改sample.conf文件，也可自行创建新conf文件

<target iqn.2008-09.com.example:server.target1>
        backing-store /mnt/big_disc_file1.tgt
        verdor_id BobMake
    </target>

5.查看tgt信息，此次我们查看tgt信息中Thin-provisioning选项为No状态

[root@centos7-nfstest ~]# tgtadm --mode target --op show
    Target 1: iqn.2008-09.com.example:server.target1
        System information:
            Driver: iscsi
            State: ready
        I_T nexus information:
        LUN information:
            LUN: 0
                Type: controller
                SCSI ID: IET     00010000
                SCSI SN: beaf10
                Size: 0 MB, Block size: 1
                Online: Yes
                Removable media: No
                Prevent removal: No
                Readonly: No
                SWP: No
                Thin-provisioning: No
                Backing store type: null
                Backing store path: None
                Backing store flags: 
            LUN: 1
                Type: disk
                SCSI ID: IET     00010001
                SCSI SN: beaf11
                Size: 5369 MB, Block size: 512
                Online: Yes
                Removable media: No
                Prevent removal: No
                Readonly: No
                SWP: No
                Thin-provisioning: No
                Backing store type: rdwr
                Backing store path: /mnt/big_disc_file1.tgt
                Backing store flags: 
        Account information:
        ACL information:
            ALL

6.配置tgtd支持Thin-Provisioning

[root@centos7-nfstest ~]# tgtadm --lld iscsi --mode logicalunit --op update --tid 1 --lun 0 --params thin_provisioning=1
    [root@centos7-nfstest ~]# tgtadm --lld iscsi --mode logicalunit --op update --tid 1 --lun 1 --params thin_provisioning=1

再次查看tgt信息，Thin-provisionging为Yes状态

[root@centos7-nfstest ~]# tgtadm --mode target --op show
    Target 1: iqn.2008-09.com.example:server.target1
        System information:
            Driver: iscsi
            State: ready
        I_T nexus information:
        LUN information:
            LUN: 0
                Type: controller
                SCSI ID: IET     00010000
                SCSI SN: beaf10
                Size: 0 MB, Block size: 1
                Online: Yes
                Removable media: No
                Prevent removal: No
                Readonly: No
                SWP: No
                Thin-provisioning: Yes
                Backing store type: null
                Backing store path: None
                Backing store flags: 
            LUN: 1
                Type: disk
                SCSI ID: IET     00010001
                SCSI SN: beaf11
                Size: 5369 MB, Block size: 512
                Online: Yes
                Removable media: No
                Prevent removal: No
                Readonly: No
                SWP: No
                Thin-provisioning: Yes
                Backing store type: rdwr
                Backing store path: /mnt/big_disc_file1.tgt
                Backing store flags: 
        Account information:
        ACL information:
            ALL

很奇怪在这里必须用命令行才能配置tgtd支持thin-provisioning，在配置文件里面添加thin-provisioning如下，tgt信息里面thin-provisioning仍然显示No状态

<target iqn.2008-09.com.example:server.target1>
        backing-store /mnt/big_disc_file1.tgt
        verdor_id BobMake
        thin_provisioning 1
    </target>

7.从客户端连接该tgt，并查看是否支持thin-provisioning

[root@quadstor-node1 ~]# sg_vpd -p 0xb2 /dev/sdg
    Logical block provisioning VPD page (SBC):
      Unmap command supported (LBPU): 1
      Write same (16) with unmap bit supported (LBWS): 1
      Write same (10) with unmap bit supported (LBWS10): 1
      Logical block provisioning read zeros (LBPRZ): 1
      Anchored LBAs supported (ANC_SUP): 0
      Threshold exponent: 0
      Descriptor present (DP): 0
      Provisioning type: 2

注意unmap command supportd值为1。

8.测试scsi unmap命令

在iscsi客户端向sdg（iscsi target设备）写入数据块

[root@quadstor-node1 ~]# dd if=/dev/zero of=/dev/sdg bs=512 seek=1024 count=128
    128+0 records in
    128+0 records out
    65536 bytes (66 kB) copied, 0.014353 s, 4.6 MB/s

检验块是否映射

[root@quadstor-node1 ~]# sg_get_lba_status -l 1024 /dev/sdg
    descriptor LBA: 0x0000000000000400  blocks: 128  mapped

取消映射块，这里我们取消16个映射块

[root@quadstor-node1 ~]# sg_unmap -v -l 1024 -n 16 /dev/sdg
        unmap cdb: 42 00 00 00 00 00 00 00 18 00

检验unmap是否运行

查看是否已取消映射块

[root@quadstor-node1 ~]# sg_get_lba_status -l 1024 /dev/sdg
    descriptor LBA: 0x0000000000000400  blocks: 16  deallocated

查看之后未取消的映射块

[root@quadstor-node1 ~]# sg_get_lba_status -l 1040 /dev/sdg
    descriptor LBA: 0x0000000000000410  blocks: 112  mapped